EDITOR’S NOTE: Call to Earth is a NCS editorial collection dedicated to reporting on the environmental challenges going through our planet, along with the options. Rolex’s Perpetual Planet Initiative has partnered with NCS to drive consciousness and training round key sustainability points and to encourage optimistic motion.
As international temperatures rise and water shortage worsens, a nanoengineered paint developed by researchers in Australia goals to sort out each — with the stroke of a brush.
For University of Sydney scientists Chiara Neto and Ming Chiu, these rising pressures sparked an concept: a rooftop coating that could cool buildings and harvest water from the air.
That work advanced into startup Dewpoint Innovations, based in 2022 with ambitions past cooling paint to a broader rethink of how infrastructure is designed: If rooftops throughout a metropolis could replicate warmth and gather water, they could grow to be a part of the local weather answer.
In a warming world, cities have gotten warmth traps. Concrete and rooftops take up the solar’s power, elevating temperatures, resulting in what’s referred to as the urban heat island effect — the place cities expertise greater temperatures.
That is the first problem Dewpoint Innovations is focusing on: “Our paint will significantly reduce the heat load the sun puts on cities,” mentioned Chiu, co-inventor and chief know-how officer at Dewpoint Innovations.
To obtain that impact, the specifically engineered nanomaterials use a course of known as passive radiative cooling to replicate most of the solar’s power and launch warmth again into the sky — permitting roof surfaces to remain cooler than the surrounding air with out utilizing power.
Typical industrial white paint displays round 70% to 80% of incoming daylight, mentioned Distinguished Professor Baohua Jia, a nanotech professional at RMIT University in Melbourne, Australia, who’s unaffiliated with Dewpoint Innovations.
Dewpoint’s coating demonstrated photo voltaic reflectance of as much as 96% in a six-month outdoor trial reported in 2025. That greater reflectivity means much less warmth was absorbed, maintaining roof surfaces as much as 6 levels Celsius (11 levels Fahrenheit) cooler than the surrounding air and lowering warmth switch into buildings.
In a three-month subject trial in Sydney in late 2023, Dewpoint’s roof paint stayed as much as 30 levels Celsius (86 levels Fahrenheit) cooler than a typical darkish roof — translating to an estimated discount of as much as 34% in family cooling power use.
For Jia, these outcomes level to a broader potential. She believes Dewpoint’s roof coating presents a scalable strategy to curb the city warmth island impact. “This technology can potentially drastically reduce ambient urban temperatures, ease heat stress and reduce reliance on air conditioning, making it a tangible tool for climate adaptation in dense urban areas,” she mentioned.
“One of the amazing properties of having a surface that is maintaining a cooler temperature, while the rest of the environment is increasing in heat, is that it also encourages any moisture in the air to condense on its surface,” Dewpoint chief government officer Perzaan Mehta advised NCS.
It’s the identical fundamental course of that causes water to type on the exterior of a chilly glass.
While nonetheless in the growth part, in early trials, the system demonstrated that it could gather 74 liters (19.5 gallons) of water per day from a 200 sq. meter (2,153 sq. foot) roof. Metha mentioned that is roughly the quantity utilized by a five-minute bathe in areas which have extra water abundance.
It can not exchange a home’s full water provide, however Mehta mentioned it will probably function a supplemental supply: “It’ll help reduce the burden, but it’s not the miracle cure.”
Through modeling information collected up to now, Dewpoint has discovered {that a} minimal relative humidity of round 70% is required for water assortment to work — like that present in coastal, tropical areas equivalent to Singapore or the Amazon Basin in South America.
“In the tropics, you’re going to get much better performance, and that’s where we’ve seen a lot of the international interest from our products,” Mehta mentioned.
Jia mentioned passive water harvesting is certainly one of the most fun, fast-growing traits in the radiative cooling subject. While efficiency varies with humidity, wind and temperature, she mentioned, ongoing subject optimizations are enhancing water yield consistency, even in semi-arid areas.
Dewpoint sees its water seize system being utilized in a wide range of methods: the water could feed into current rainwater techniques for irrigation or be filtered for consuming and family use.
Beyond human purposes, the cooling know-how could additionally assist help wildlife, Chiu mentioned, by lowering warmth stress beneath animal shelters and offering water throughout droughts.
Between 2019 and 2020, drought and excessive warmth fueled months of bushfires across Australia, devastating ecosystems and affecting round 80% of the inhabitants. During the disaster, photographs of firefighters giving water to dehydrated koalas helped form Chiu’s considering round atmospheric water seize.
“Water capture systems could be deployed as constructive features in the middle of nowhere to generate water from the air so wildlife can have access to drinking water when they need it and they couldn’t find it anywhere,” Chiu mentioned.
“There is a future where you’d be able to purchase this paint and apply it on your roof,” Mehta mentioned.
Dewpoint is presently getting ready for extra intensive trials of its paint on Australian rooftops and probably abroad, with the aim of commercializing the product for distribution by way of Haymes Paint, an Australian-owned firm.
Andrew Brewer, group merchandise and product supervisor of Haymes Paint, advised NCS it’s excited to convey this sustainable know-how to market.
Brewer famous the barrier to entry into an already-established business might be robust: “Project builders default to known products,” he mentioned, including that adoption will depend upon independently validated efficiency, whether or not the power financial savings justify the upfront price and compatibility with normal utility strategies.
“Over the longer term, as sustainability and heat management increase in importance in construction, we foresee increased demand for products that contribute to a cooling effect,” Brewer added.
Mehta mentioned that, “In general, we expect to be at a similar price point to functional paints, which tend to be 50-100% more expensive than regular paint,” noting that pricing can be market particular.
Other extremely reflective, ultra-white paints are in growth to assist cool buildings and reduce down on air conditioning utilization. Researchers are even tapping into machine studying to create an AI-designed cooling paint — that could allow buildings to remain between 5 to twenty levels Celsius (41 to 68 levels Fahrenheit) cooler than conventional paint throughout noon publicity.
Radiative cooling merchandise nonetheless face challenges like sturdiness over time, decreased efficiency in cloudy or variable climate, barely greater upfront prices and a scarcity of standardized testing and constructing codes, Jia advised NCS. But these are actively being addressed, she added, with enhancements in supplies, design and manufacturing anticipated to make the know-how extra dependable and broadly adopted.
As analysis and industrialization proceed, Jia says the subject of passive radiative cooling will play “an increasingly vital role in cooling cities, cutting carbon emissions and securing water supplies, all without consuming precious energy or relying on artificial refrigerants.”
Dewpoint’s final imaginative and prescient is to see its paint grow to be integral to city planning and growth: “I think it would be fantastic to see Dewpoint as part of the toolkit that city planners and architects have going forward,” Mehta mentioned, “and have products like ours become part of the regulatory framework of how we think about cities being designed.”